your momentum should carry you through into an end fielding position (her back leg figure fouring behind her stride leg is not helping either - it should be dragging forward).
My 10 YOA DD working on this and I have her back leg coming up like a figure four, kind of like what is shown in frame 8. Looking the model pitching thread this seems to be what the majority of the Ps are doing, it might have to do with the pitches they are throwing. Sarah Pauly is one example.
Is it “bad” to kick the drag foot behind the plant foot for a fastball?